In the process of atherosclerosis, as resulting from occlusive arterial disease, the inner lining of an artery receives deposits of fatty substances, cholesterol, and cellular waste products. The deposits form plaques within the artery that reduce or stop the flow of blood through the artery and that can dislodge from the arterial wall to cause a heart attack or stroke in a subject. One of the most common sites of occlusive arterial disease is the carotid artery. Health care professionals, such as surgeons, typically perform an endarterectomy within the carotid artery to remove the plaques and minimize the risk of stroke within the patient.
During an endarterectomy procedure, a surgeon typically clamps an occluded (or partially occluded) carotid artery both distal and proximal to the site of the occlusion and forms an incision (e.g., arteriotomy) in the artery at the occlusion site. To allow cerebral blood flow during the procedure, the surgeon utilizes a temporary shunt to allow blood to flow from the patient's heart to the patient's head while bypassing the operative site. Conventionally, the surgeon incises the carotid artery, places a shunting device (e.g., shunt) within the carotid artery, and orients the shunt proximally in the common carotid artery and distally past a bifurcation of the carotid artery (e.g., where the carotid artery divides into the internal carotid artery and the external carotid artery) into the internal carotid artery. The surgeon releases the distal and proximal clamps such that the shunt carries blood from the heart and to the internal carotid artery. The surgeon then accesses the artery, via the incision, and removes atherosclerotic plaques from the inner wall of the carotid artery.
In certain cases, the surgeon utilizes a balloon shunt as the shunting device during the endarterectomy procedure. FIG. 1 illustrates an example of a conventional balloon shunt 10. The balloon shunt 10 includes a conduit 12 having occlusive balloons 16, 14 located, respectively, at a first end 20 and a second end 18 of the conduit 12. The first occlusive balloon 16 connects to an inflation source 25 via a first fluid inlet conduit 26 and a first stopcock 28. The second occlusive balloon 14 connects to an inflation source 21 via a second fluid inlet conduit 22 and a second stopcock 24. Conventionally, the first occlusive balloon 16 conventionally has a fluid capacity of approximately 0.25 milliliters (ml) and an approximate 8 millimeter (mm) diameter at maximum liquid capacity (e.g., when inflated). Also, the second occlusive balloon 14 has a maximum fluid capacity of approximately 1.5 ml and an approximate 14 mm diameter at maximum fluid capacity (e.g., when inflated).
During operation, for example, the surgeon incises a carotid artery, inserts the second end 18 of the conduit 12 within a common carotid artery, and inserts the first end 20 of the conduit 12 into an internal carotid artery. The surgeon then inflates the balloons 14, 16 using an inflation fluid, such as a saline solution. Inflation of the balloons secures the shunt 10 to the carotid artery and occludes the carotid artery. The inflated balloons 14, 16 minimize the flow of blood within the arteriotomy site (e.g., cause the blood carried by the shunt 10 to bypass the arteriotomy site).
When the surgeon inserts the first occlusive balloon 16 of the shunt 10 within the internal carotid artery and inflates the balloon 16, the balloon creates pressure against an inner wall of the internal carotid artery, thereby securing the first occlusive balloon 16 within the internal carotid artery. The internal carotid artery, however, has a pressure sensitive structure or physiology that is susceptible to damage when exposed to relatively high or excessive pressures. As such, the conventional first fluid inlet conduit 26 includes a safety balloon 30 that limits the ability for a user to over-inflate the first occlusive balloon 16 and generate a relatively excessive pressure within the internal carotid artery.
For example, if a user over-inflates or over-pressurizes the first occlusive balloon 16 via the inflation source 25, the extra pressure diverts to the safety balloon 30, thereby inflating the safety balloon 30 and minimizing damage to the internal carotid artery. In the case where the safety balloon 30 inflates, the user removes fluid from the safety balloon 30 via the inflation source 25 to achieve an appropriate pressure within the first occlusive balloon.
The first fluid inlet conduit 26, in one arrangement, also includes a balloon sleeve 32 that operates in conjunction with the safety balloon 30. When the balloon sleeve 32 covers the safety balloon 30, the sleeve 32 limits expansion of the safety balloon 30 and minimizes transmission of fluid from the inflated first occlusive balloon 16 to the safety balloon 30.
For example, assume that the user inflates the first occlusive balloon 16 within the internal carotid artery. Further assume that the balloon sleeve 32 does not engage the safety balloon 30 (e.g., as shown in FIG. 1). In such an arrangement, during an endarterectomy procedure, fluid from the inflated first occlusive balloon 16 can travel from the first balloon 16, through the second fluid inlet conduit 26 and to the safety balloon 30, thereby inflating or expanding the safety balloon 30. As a result, the first occlusive balloon 16 deflates and becomes loose within the internal carotid artery, thereby leading to leakage of blood into the endarterectomy site. In the case where the balloon sleeve 32 engages or covers the safety balloon 30, the balloon sleeve 32 minimizes the ability for fluid from the inflated first occlusive balloon 16 to travel to, and expand, the safety balloon 30. The balloon sleeve 32, therefore, helps to minimize or prevent deflation of the inflated first occlusive balloon 16 during an endarterectomy procedure.
Additionally, in the balloon shunt 10, manufacturers conventionally shade the second occlusive balloon 14 and the second stopcock 24 with similar or corresponding colors 32 (e.g., a surface coloring or color coating) while maintaining the first occlusive balloon 16 and the first stopcock 28 with no detectable coloring. For example, a manufacturer forms the second balloon 14 and the second stopcock 24 each with a blue coloring and maintains the first occlusive balloon 16 and the first stopcock 28 with a substantially white shade.
The similar coloring 32 of the second occlusive balloon 14 and the second stopcock 24 identifies a correspondence between the second balloon 14 and the second stopcock 24. Therefore, during surgery, when the surgeon identifies a blue colored stopcock 24 within a surgical field (e.g., regardless of the positioning of the blue colored stopcock 24 relative to any other stopcocks present within the surgical field) and activates the inflation device 21 associated with the colored stopcock 24, the surgeon intuitively knows that such activation will inflate the blue colored second occlusive balloon 14 of the shunt device 10. Additionally, the similar coloring 32 of the second occlusive balloon 14 and the second stopcock 24 allows a surgeon to distinguish, within a surgical site, the second stopcock 24 and second occlusive balloon 14 from the conventionally uncolored first stopcock 28 and first occlusive balloon 16.
Also in the conventional balloon shunt 10, manufacturers include markings 36 on the shunt 10 to allow users to identify a correspondence between a particular stopcock and a particular balloon. For example, a manufacturer typically includes a first black band 36-1 on the conduit 12 in proximity to the second occlusive balloon 14. The manufacturer also includes a second black band 36-2 on the second stopcock 24. The presence of the bands 36-1, 36-2 on the shunt 10 allows a surgeon to identify the second stopcock 24 as corresponding to the second occlusive balloon 14 during a surgical procedure.